Honestly, The Shade being absent in the story is definitely not high on my list of issues with the story personally. Plenty more for me to dislike.
True 'nuff, but it further illustrates just how careless DC is with its alleged "shared universe", and how they go through fits of just throwing stuff at the wall to see what sticks and never caring what a mess they make.
The Shade might keep his head down rather than tangle with Karkull and Obsidian, or worse, Obsidian, Eclipso and freakin' Mordru (though at least he put in an appearance in the latter storyline), but Jean Loring? He'd swat her like a gnat. (Or if he was feeling really generous he might drop her, all wrapped up in Shadowstuff like a present, at Batman's feet.)
I think I'll go start a Shade Appreciation thread.
I mean, it would have been nice to see him at the funeral at the very least. But I'm not sure he could have added a ton to the investigation, especially given how badly it was written anyway. Loring at the time didn't have any powers, so apprehending her wasn't really the difficult part.
To quote Linkara, "This! Comic! Sucks!"
(He thinks Heroes in Crisis sucks worse, which is really saying something!) http://atopthefourthwall.com/heroes-in-crisis/